Efficiently compute sums of diagonals of a matrix | A simple C # program to find sum of diagonals ; Condition for principal diagonal ; Condition for secondary diagonal ; Driver code
using System ; public class GFG { static void printDiagonalSums ( int [ , ] mat , int n ) { int principal = 0 , secondary = 0 ; for ( int i = 0 ; i < n ; i ++ ) { for ( int j = 0 ; j < n ; j ++ ) { if ( i == j ) principal += mat [ i , j ] ; if ( ( i + j ) == ( n - 1 ) ) secondary += mat [ i , j ] ; } } Console . WriteLine ( " Principal ▁ Diagonal : " + principal ) ; Console . WriteLine ( " Secondary ▁ Diagonal : " + secondary ) ; } static public void Main ( ) { int [ , ] a = { { 1 , 2 , 3 , 4 } , { 5 , 6 , 7 , 8 } , { 1 , 2 , 3 , 4 } , { 5 , 6 , 7 , 8 } } ; printDiagonalSums ( a , 4 ) ; } }